Principal Software Engineer

08th July, 2026We are looking to recruit an experienced and highly skilled Principal Software Engineer to lead the design, development, and optimisation of our mission-critical communication infrastructure. This role is central to ensuring the reliability, performance, and scalability of systems vital for public safety and essential services. You will act as a technical leader, mentoring other engineers and driving best practices across the development lifecycle. Working alongside other Software application team members, the successful candidate will be responsible for the development, integration and maintenance of the existing Web. Come and join Sepura Ltd at an exciting time of growth and progress your career within this innovative technology company, based in Waterbeach, Cambridge.Role: Specific responsibilities will include:Lead the architecture, design, and implementation of high-performance, resilient, and secure communication systems using C#/.NET.Develop robust, low-latency applications that handle high-volume data traffic (e.g., messaging queues, real-time data processing).Drive technical vision and strategy for the platform, ensuring alignment with long-term business goals and industry standards.Conduct code reviews, establish coding standards, and implement continuous integration/continuous delivery (CI/CD) pipelines.Troubleshoot and resolve the most complex technical issues, ensuring maximum system uptime and reliability.Mentor and guide mid-level and senior developers, fostering a culture of technical excellence and innovation.Day to Day: Our customer base includes many different industries and markets around the world. Our complete TETRA and LTE solutions have been developed specifically for users in multiple sectors to face their critical communications challenges. There is no such thing as a typical day here at Sepura. You will be supported by your manager and team, as well as collaborating with other departments across the business. The Software

Team at Sepura follows an Agile development process centred around the heartbeat of Scrum ceremonies. During each sprint you could be taking on several tasks related to several of the responsibilities listed above.After 3 months in the role, the successful candidate could be 2 days home and 3 days in the office - with the requirement to be in the office on an AD-hoc basis when required.What you need to succeed:Must-haves:QualificationsDegree in relevant disciplineExperience and Skills10+ years of professional software development experience, with significant focus on C# and the .NET framework (including .NET Core/.NET 5+).Deep expertise in designing and developing highly scalable, distributed systems (e.g., microservices architecture).Experience with development of Web Applications.Proven experience with protocols and technologies common in communication or high-availability systems (e.g., TCP/IP, gRPC, messaging services like Kafka or RabbitMQ).Expertise in performance tuning, concurrency, and multithreading to achieve low-latency processing.Strong understanding of security principles related to critical infrastructure.Excellent problem-solving, communication, and technical leadership skills.UI front-end frameworks such as WPF, MVVM, MVP or MVC Nice to have:Experience and SkillsPlanning software projects (considering resourcing, task dependencies, tool requirements, etc)Working in an Agile SCRUM environmentExperience using virtual environment such as Docker.Experience using Kotlin/JavaToolchain configuring (CI/CD, Version Control, Defect tracking tools, code analysis, automated testing)